Big Bang Theory executive producer Bill Prady wouldn’t reveal why the show’s geek squad ends up in “superheroine drag” in the April 12 episode — that’s Simon Helberg as Batgirl, Jim Parsons as Wonder Woman, Johnny Galecki as Supergirl, and Kunal Nayyar as Catwoman — but it’s safe to say it involves the return of Sheldon’s arch-nemesis, Evil Wil Wheaton. “I will say this,” Prady adds, “this is not the worst thing that happens to someone in this episode.”